Protective Effects Of Small Heat Shock Protein 27 On Brain Endothelium In Chronic Hypoxia

AIMTo establish a model of chronic cerebral endothelium hypoxia,the expression of heat shock protein 20（Hsp20）,heat shock protein 22（Hsp22）,heat shock protein 27（Hsp27）,tumor necrosis factor-α（TNF-α）and interleukin-1 beta（IL-1β）in endothelium were observed under chronic hypoxia.And the relationship between Hsp27 and inflammatory factors under chronic hypoxia was studied to explore the possible protective effect of Hsp27 on cerebral endothelium.METHODSMouce brain endothelium cells bend.3 was cultured in hypoxia（2%O₂,5%CO₂and93%N₂）to simulate chronic cerebral hypoperfusion in vitro.Cultured cells was observed in normoxia and hypoxia at 24h,48h and 72h.Cell morphology was observed using inverted Fluorescence microscope and the activity of cells was detected by CCK-8.The expression levels of Hsp20,Hsp22,Hsp27,TNF-αand IL-1βwere detected by western blot and RT-q PCR.To test the association between Hsp27 and TNF-α,the expression of inflammatory factors was measured after endothelium cultured with KRIBB3,an inhibitor of Hsp27.RESULTS1.Under the microscope,chronic hypoxia culture cells shrank and became round,the cells became narrow,the intercellular space widened and the number of living cells decreased.2.With the prolonged culture time of chronic hypoxia,the cell viability decreased obviously compared with control（P<0.05）.3.After chronic hypoxia treatment,the expression of Hsp20,Hsp22 and Hsp27 were higher than that of control group（P<0.001）.4.After chronic hypoxia treatment,the expression of TNF-αand IL-1βwere higher than that of control group（P<0.001）.5.The expression of inflammatory factors in the cells treated with Hsp27 inhibitor were significantly higher than that in the untreated cells（P<0.001）.CONCLUSION1.Chronic hypoxic cultured endothelium can be used as a cell model of chronic cerebral hypoperfusion in vitro,and the cell viability decreases with the time of hypoxia.2.Chronic hypoxia increases the expression of small heat shock protein in the endothelium.3.Chronic hypoxia increases the expression of inflammatory factors in the endothelium.4.Hsp27 protects against cerebral vascular injury caused by chronic hypoxia by reducing inflammatory response.